Hunting a Memory Leak in 19.07.1 WRT1900ACS

As stated above mwlwifi sets up some large buffers for its queues, but is memory still decreasing.

@fantom-x, not sure how something being mentioned one time equates to being pushed hard.

Running on 1 Radio would be possible, but the main traffic (>90%) is going through the 5G radio so I'd point to that radio.

Here you go. There is a thread on the forum that is discussing the latest version of this driver. You might want to look into that to see if the new one is better. I have no experience with this router/driver, so cannot help any further. Good luck.

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There is no new driver, that is It is simply a new firmware BLOB that was put out with the latest OEM SW release. I don't think anything will change regarding memory usage as there is no leak happening with the current mwlwifi to my knowledge. I run two different wrtpac devices (mamba, rango) and I am not seeing anything untoward with mwlwifi here. Actually that BLOB is not for the device in question.

BTW, depending on how long it takes to make the router non-operational, you might want to consider restarting wifi daily in the middle of the night. Something like below (untested):

cat /etc/crontabs/root 
17	3	*	*	*	(echo "Restarting wifi"; /sbin/wifi; echo "Done") 2>&1 | /usr/bin/logger -t "wifi-restart"

@anomeome I'll test the new BLOB following your steps here

@fantom-x the memory is consumed up to 100% in a couple of hours, so restarting Wifi may be needed twice a day. That'll make the trick until I find another solution if the update of the firmware does not work. Eventually I'd start looking for another Router (Netgear R7800) :frowning:

No point, that new firmware is only for the venom and rango.

Well that would mean only @fantom-x option (scheduled restart of WiFi) is on the table

I don't follow how it has been arrived at that mwlwifi is leaking. All you did was shut down wifi, freeing up the queue buffers. If mwlwifi was the issue, there would be a lot of people experiencing the issue, including myself.

If you are wanting to hide the issue may as well do a nightly reboot.

Also mwlwifi would not explain the leak on TP-Link Archer C7 v2.

I didn't mean that the leak is inside mwlwifi, so far the only thing I obseved, as you said, was the memory being released after stoping the wifi.

Any guidance to help me dig something deeper than "wifi down" for trying to find out where my memory is leaking is more than welcome.

@patrakov is completely right, although the memory leak of the C7 might not have the same root as mines.

That is the one I got. Rock solid with non-ct wifi firmware/driver.

Did you move to 19.07.2 and still experience the issue, if so inclined you could give master a try, runs just fine.

I'm now on 19.07.2 and still having issues, yes :confused:
Is master the codename for the Netgear R7800?

development snapshot, but that changes anytime there is a reason for your target to be rebuilt; meaning grab everything you need as it may be different the next time you need something, and no LuCI OOTB.

Now I have two questions:

  1. If there is a snapshot built today that means that there were changes relevant to my device?
  2. As soon as i upgrade with linksys_wrt1900acs-squashfs-sysupgrade.bin I'm losing LuCi OOTB?
  1. If there is a snapshot today, then there are changes relevant for some device, not necessarily yours.
  2. Yes, you lose Luci, but you can still ssh into your router and install it from the command line.
  3. Make sure you install all the needed packages on the first day, because installation of any package that requires any extra kernel module will fail once there is a new snapshot.
  4. Backup everything (including the list of installed packages) before trying a snapshot.

Installation of snapshots is expected to be safe, you can always restore to the stable release, restore the backup and reinstall the packages.

I found it.
The router was underpowered.


the problems started and the first culprit was my new

I disconnected it from the router so I thought probable source of problem was isolated. What I did not do was to power it off. And that's why the memory leak was still there. The NAS was sucking up enough power to make the Router run underpowered.
I confirmed that whenever I switch the NAS on the Router starts to leak memory and, as soon as I switch the NAS off the router recovers the leaked memory back.

Honestly, sorry for not realizing before, I really thought that it was a SW memory leak, but it seems it was caused by the router running underpowered.
Thanks again for the time you took for helping me hunt this memory leak.

Lesson of the day: Do not plug all your stuff on the same electric phase.

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I'm not going to question your conclusions... but this is the weirdest consequences of running a device underpowered that I have ever seen.

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So the NAS may be sending some IP packets that the router does not like. Could you please confirm by having the NAS in a different network segment?